On Sun, Jan 12, 2020 at 6:44 AM Doug McIlroy <doug@cs.dartmouth.edu> wrote:

> Mention of elevators at Tech Square reminds me of visiting there
> to see the Lisp machine. I was struck by cultural differences.
>
> At the time we were using Jerqs, where multiple windows ran
> like multiple time-sharing sessions. To me that behavior was a
> no-brainer. Surprisingly, Lisp-machine windows didn't work that
> way; only the user-selected active window got processor time.
>
> The biggest difference was emacs, which no one used at Bell
> Labs. Emacs, of course was native to the Lisp machine and
> provided a powerful and smoothly extensible environment. For
> example, its reflective ability made it easy to display a
> list of its commands. "Call elevator" stood out amng mundane
> programmering actions like cut, paste and run.
>
> After scrolling through the command list, I wondered how long
> it was and asked to have it counted. Easy, I thought, just
> pass it to a wc-like program. But "just pass it" and "wc-like"
> were not givens as they are in Unix culture.  It took several
> minutes for the gurus to do it--without leaving emacs, if I
> remember right.
>

It should have been something like  (list-length (command-list-fn)) but
I'll bet that ? was bound to a complicated function that just displayed the
results and didn't properly abstract out the UI (printing) from the data
collection (getting a list), which is what made it so hard. I've had so
many gnu emacs experiences like this over the years, but to the community's
credit, there's fewer and fewer as time goes by.

ObUnix: This shows the power of having the right abstractions and being
disciplined to code to those ideal abstractions any time there might be
reuse...

Warner